1. Field of the Invention
This invention relates to a working vehicle having a propelling transmission for transmitting power of an engine to drive wheels, the propelling transmission being attached to body frames as offset to one side transversely of a vehicle body to produce a utility space in the other side, with a power take-off (PTO) apparatus for transmitting power supplied from the propelling transmission to an external working implement.
2. Description of the Related Art
The above working vehicle, when an external working implement such as a rotary plow is connected to the rear of the vehicle body, transmits power supplied from the propelling transmission to the external working implement through the PTO apparatus.
A tractor which is a typical example of working vehicle may be used as a cultivating machine with a rotary plow connected to the rear of a tractor body. Alternatively, the tractor may be used as a grass cutting machine or a dust collecting machine with a mower unit or a dust collector connected to the vehicle body between front and rear wheels, and a grass catcher or a dust catcher attached to the rear of the vehicle body. A receiving portion of the grass catcher or dust catcher is connected to a discharge portion of the mower unit or dust collector through a transmitting duct. A blower is driven to transmit grass clippings or dust to the grass catcher or dust catcher.
When the tractor is constructed to act as a cultivating machine, a power transmission line from the propelling transmission through the PTO apparatus to the rotary plow tends to bend to a great extent three-dimensionally with the rotary plow moving up and down. As a result, transmission noise tends to be generated from connections in the power transmission line.
When the tractor is constructed to act as a grass cutting machine or dust collecting machine, the transmitting duct usually extends from the mower unit or dust collector outwardly of the tractor body from between the front and rear wheels and to the grass catcher or dust catcher. Thus, the transmitting duct provides an elongated transmission path with many bends. This results in grass or dust transmitting difficulties and enlarged transverse dimensions of the tractor body to encumber driving.
The object of this invention is to provide a working vehicle free from inconveniences in power transmission or grass or dust transmission when converted to a cultivating machine with an external working implement such as a plowing implement attached, or when converted to a grass cutting or dust collecting machine with an external working implement such as a mower unit or dust collector attached.
The above object is fulfilled, according to this invention, by a working vehicle having a propelling transmission as set forth at the outset hereof, comprising a PTO apparatus for transmitting power supplied from the propelling transmission to an external working implement, the PTO apparatus includes an input shaft extending longitudinally of the vehicle body and drivably connected to the propelling transmission, and an output shaft extending parallel to and spaced from the input shaft and drivingly connected to the external working implement; and a mounting mechanism system for attaching the PTO apparatus to vehicle body frames, the mounting mechanism system selectively fixing the PTO apparatus in at least two pivotal postures about the input shaft.
With this construction, an optimal position may be selected for the output shaft of the PTO apparatus according to an external working implement to be attached. Moreover, since the position of the input shaft is unchanged, a construction is employed to turn the PTO apparatus about the input shaft, which realizes a simplified mounting mechanism system.
In a preferred embodiment of this invention, the mounting mechanism system includes a first mounting mechanism and a second mounting mechanism, each mounting mechanism including a support platform for detachably attaching the PTO apparatus, and a mounting base connected to the support platform and detachably attached to the vehicle body frames. The PTO apparatus may be fixed reliably by using a support platform suitable to each different pivotal posture of the PTO apparatus. As a particularly preferred embodiment, the support platform may include a first support plate for supporting the PTO apparatus with the output shaft offset to the one side transversely of the vehicle body, and a second support plate for supporting the PTO apparatus with the output shaft in a substantially middle position transversely of the vehicle body. This construction provides two typical positions of the output shaft in a simple way.
In another preferred embodiment of this invention, when the PTO apparatus is attached to the vehicle body frames by using the first support plate, the PTO apparatus as a whole is disposed in the side to which the propelling transmission is offset, a dust transmitting duct extending longitudinally of the vehicle body through the utility space. In this construction, the PTO apparatus is offset to the same side to which the propelling transmission is offset, to produce a sufficient space between one of the right and left rear wheels and the power takeoff apparatus to accommodate the dust transmitting duct. Thus, when the working vehicle is converted to a grass cutting machine or a dust collecting machine, the transmitting duct extending between the right and left rear wheels can quickly and efficiently transmit grass clippings or dust to a grass catcher or a dust catcher. The machine is easy to drive since the overall transverse dimensions are not increased.
In a further preferred embodiment of this invention, when the PTO apparatus is attached to the vehicle body frames by using the second support plate, a power transmission line extends substantially linearly with respect to a transverse direction of the vehicle body, from the output shaft of the PTO apparatus to a plowing implement acting as the external working implement. With this construction, considering that the plowing implement apparatus usually has a power input portion thereof located in the middle position, no great three-dimensional bending occurs with the power transmission line from the output shaft of the PTO apparatus to the plowing implement. Consequently, when the working vehicle is converted to a cultivating machine, connections in the power transmission line are bent to a less degree, thereby hardly producing transmission noise, even when the plowing implement moves up and down.
Other features and advantages of this invention will be apparent from the following description of the embodiment to be taken with reference to the drawings.